The invention relates to an arrangement for catching or collecting seepage water from depositories.
In the deposition of wastes, seepage water is produced. Depending on the composition of the waste matter, depositories may be charged with pollutants for decades or centuries. According to the present state of the art, depository seepage water is caught by seals, is collected and transported to a treatment facility.
Known types of seals are mineral seals (for example, clay, bentonite with water glass), bitumen seals or foil seals. Although such seals are basically suitable for their purposes, their reliability is limited. This is confirmed from practice and by the results of research projects (conducted by or under the West German Federal Environment Office, 1984). The localization and repair of leaks are problems for which no suitable solution has been provided to date. As a result, depositories are in principle no longer permitted in some water protection zones in certain countries. This limitation makes it impossible in large parts of those countries to find sites for residential garbage depositories. Sites for special waste depositories are generally difficult to get approved.
Advantageously, seepage water is collected separately from different lots. The reason for the separate collection is the different pollutant loading of different depository sections. By separate seepage water collection, contaminated depository sections can be localized and the seepage waters thereof can be channeled to suitable treatment facilities. If separate treatment is not carried out, mixed waters are drained off due to a dilution effect, for which mixed waters a separate treatment (such as a third purification stage) can hardly be considered. In this way, harmful substances are released into the environment unnecessarily. Reasons for the prevalent mixed water drainage include the insufficient reliability of drain lines due to a lack of strength and the plethora of hardware. Available data is inadequate to supply proof of fracture strength of commercial drain pipes for pressures which commonly prevail in a depository.
While other sealing systems such as that of ROLLINS, U.S.A., provide, in addition to several artificial seals, a fixed concrete bed, which provision increases the general reliability, the same reservations apply as in the other types of seals with respect to approval procedures because of the still existing residual uncertainty.
It is an object of the invention to provide an improved arrangement for collecting percolating water in waste depositories wherein the reliability of the sealing body can be checked visually at any time and the seal can be repaired simply and quickly in the event of damage.